Throughout history, the monuments of the ancient world have captured our imagination. Stonehenge, the Great Pyramids of Giza, and the megalithic circles of Avebury, these awe-inspiring structures have often been attributed to a people far less sophisticated than ourselves. Yet, as we explore the origins and purposes of these monuments, we encounter a striking tension. Archaeologists like Aubrey Burl and Richard Atkinson, wary of over-interpreting the role of astronomy in ancient cultures, caution against seeing the stars as the guiding force behind the megaliths. According to their view, these ancient builders, painted as "howling barbarians", living in fear of nature, were far more concerned with practical matters and survival than celestial navigation. The very idea that the builders of sites like Avebury might have used astronomical knowledge to track time, predict seasons, or mark the heavens is dismissed as speculative fantasy.

   But perhaps the true picture is more complex than this. What if, in 3000 BC, the same time that many of these extraordinary structures were being built, the foundations of astronomy had already been laid? What if these people were not primitive, but possessed a sophisticated understanding of the night sky?

   In this article, we will examine the evidence presented in texts specifically on the Pleiades, a culturally important asterism in the constellation Taurus, which shows that astronomy was alive and well in the neolithic. 

1. Challenging Assumptions About Neolithic Life

   Astronomy is sometimes used as a theory to explain the design and positioning of henges, stone circles, and other megalithic monuments, and pyramids. Yet it is not a commonly accepted one. Aubrey Burl, for example, cautions against over-reliance on astronomical theories, which he views as speculative and potentially reductive. Aubrey Burl wrote in his book on Avebury:

   According to this view, interpreting an ancient monument in relation to astronomical links, present in the location, dimensions, and geometry of the site, or notches on distant hillsides where the sun might once have risen or set in, is futile. It is on roughly the same epistemologically shaky ground as interpreting megalithic monuments as landing pads for UFOs. As Burl goes on to say, “Astronomy, geometry, psychometry or any one little and improbable piece of the past” are simply not relevant to understanding the lives to prehistoric people. Burl is clear that he is focused on understanding the lives of the people who built Avebury, and used it as a site, for whatever purpose. Is it far-fetched to paint a picture of Avebury builders and dwellers for whom the night sky was a huge part of their lives, however? Is it improbable to believe that a monument could have been constructed in 3000 BC for the purpose of monitoring the passage of time and interpreting the motion of the moon, stars and planets? Burl states that he is “much concerned with the beliefs of the people who built Avebury”, yet worried that an interpretation of the site as linked to astronomy is limiting. Is there perhaps a tension there? 

   Burl is clear in his own mind that the “absence of any firm background for so many of our most interesting sites” allow “the composers of strange theories”, who create “Utopian or UFOnian fantasies, more phony than factual, that distort some of our ancestors’ most splendid works”. Yet, almost in the same breath, Burl announces several things he is quite certain of, in relation to the ancient world at Avebury: 

   In the wake of a repudiation of “strange theories” with “no firm background”, this description of “early man” by Burl is surprisingly full of certainty. How can he know that the minds of “Neolithic peasants” were full of fears of the “unknown, darkness”, etc? This characterisation, while evocative, may itself lack firm evidence and risks oversimplifying prehistoric life. Furthermore, there is no evidence that the builders and users of Avebury were half-wits, who trembled at night-fall, and whose minds were weak. In addition to Aubrey Burl, several scholars have expressed scepticism regarding the astronomical interpretations of megalithic monuments. Clive Ruggles, a prominent figure in archaeoastronomy, has noted the challenges and controversies within the field. He observed that the development of archaeoastronomy has "not been without controversy, as it often pitted astronomers against archaeologists." The British prehistorian and archaeologist, Richard Atkinson famously wrote:

   Looking at the monuments in terms of their position, size, location and geometry is something there is actually data for - as opposed to the state of mind of someone 5000 years ago. 

   There is evidence that in 3000 BC astronomy was in very good shape and was already well established. Much of this evidence is in the stone structures themselves. Here, the aim is to show through historical texts alone that in 3000 BC, and before that, that astronomy was sophisticated and well established. One way of looking into this is by analysing accounts that exist of the Pleiades.

2. The Pleiades

   The Seven Sisters, or the Pleiades, a cluster of stars in the constellation Taurus, have been prominent in calendars and myths around the world for centuries.

   The passage highlights not just the mythological richness of the Pleiades but their astronomical and calendrical importance across cultures. They divided the year into two parts according to Hesiod, a Greek poet from the 8th century BC: when they set in the morning, this marked the start of winter, and when they rose in the summer, this marked the start of summer. Hesiod wrote one of the oldest known works describing the practical use of astronomy in agriculture.

   Hesiod advises his readers to start ploughing when the Pleiades set, and start harvesting when the Pleiades rise. By this he presumably means, when they set at sunrise for the ploughing, and when they rise at sunset for the harvesting. Indeed, in the spring, the Pleiades rise early in the morning, and in the autumn, they set in the evening, roughly paralleling the Sun’s seasonal movement. This made them a natural marker for agricultural activities. But there is a long period of time between the rising of the sun and the rising of the Pleiades at the spring equinox, in our epoch. In Athens, in Greece, Hesiod’s part of the world, this year (2025), at the equinox the sun will rise at 4:27, and the Pleiades will rise well over two hours later at 6:51. 

   A similar seasonal marker to the equinox is the equilux, when day and night are equal. The equinox, as defined today, is the moment the sun crosses the celestial equator, resulting in equal daylight and nighttime hours. However, this doesn't perfectly align with the observable equilux. For Hesiod, the equinox may well have meant the time when daylight and darkness seemed roughly equal, aligning more with the equilux. It’s possible that Hesiod and other ancient authors used observable phenomena like the equilux to approximate the equinox. As there are only three or four days difference between the two events, the equilux will be used here.

   This year, in Athens still, on the 16-17th April, when the equilux occurs, the sun will rise at 4:33 and the Pleiades at 7:08. On both the equinox and the equilux, the sun and the Pleiades rise early in the morning, but there is a long period of time, well over two hours, between these risings. As the days go by in spring, the Pleiades rise gradually earlier and earlier in the morning, and the sun rises gradually later and later in the morning. There must therefore be a day on which the times of the risings of the sun and the Pleiades roughly match. 

   The reference to the time in spring is very vague with Hesiod, and for those of us who do not plough and live in Greece, it’s difficult to know what the date would have been on that basis alone. Using the Stellarium software, we can find out what time of year the risings of the sun and the pleiades would have matched, in Hesiod’s time. Hesiod is thought to have lived between 750 and 650 BC. In 700 BC on the equilux,(6) the sun rose at 4:35 in Athens, and the Pleiades rose at 5:22. There is much less of a gap between these two risings at this period in time than at our own epoch, with only just under an hour. As a result, we can assume that if we go back in time a little further, there must have been a point at which the risings of the morning sun and the Pleiades would have coincided in spring. However, to find the date in Hesiod’s time of the rising of the sun and the Pleiades together in spring, Stellarium shows this would have been on the 14th April, both rising at 4:00. This date is 24 days after the equinox and 28 days after the equilux. 

   The heliacal rising of the Pleiades in spring, however, when these stars would have been visible for just a few moments before dawn, would have been at around the 3rd-4th May. On those days, when the Pleiades appeared at the horizon, the sun would have been at about -9 degrees altitude. This date is 44 days after the equinox, and 48 days after the equilux. If the rising of the Pleiades occurred at the same time as, or just before the sunrise at the spring equinox, clearly this would have been a long time before Hesiod’s own time.

3. Al Bīrūnī and Denis Pétau

   
   

 The Pleiades are associated with the “cutting” of the year into two parts in many ancient cultures. In the in the Atharvaveda, a Hindu text compiled around 1200-1000 BCE, the Pleides are known as the "Kṛttikā", which means "the Cuttings", referring to the stars that marked the division of the year or the transition of seasons. If this is a reference to dividing the year into two roughly equal parts, presumably at the equinox or equilux, then these many traditions could also go back very far in time. In his 1963 book, Richard Hinckley Allen wrote: 

  The 11th century scientist Al Bīrūnī had noticed that the coincidence of the spring equinox rising of the sun and the Pleiades must have dated to about 3000 years before Alexander (who died in 323 BC). Modern software, Stellarium, confirms this alignment, highlighting the accuracy of ancient observations.

   Checking for this date (3300 BC), the day of the spring equilux, 14 April, in Athens, the sun rose at 4:31 and the Pleiades at 3:52. The rising of the Pleiades and the sun at the very same time was therefore not what Al Bīrūnī had calculated, but instead the heliacal rising of the Pleiades, when the Pleiades were visible just before dawn. On the equilux in 3300 BC, at 3:52 when the Pleiades rose the sun was at altitude -8, which means these stars may have been briefly visible as they rose just before dawn. It’s difficult to actually see these stars in the breaking dawn light on Stellarium, but perhaps the Pleiades would have been visible to sharp-eyed observers at that time. 

In Alexandria, a similar situation would have played out.

    In his 18th century Histoire de l’Astronomie Ancienne, Jean-Sylvain Bailly noted that the 17th century Jesuit astronomer Denis Pétau had come to the conclusion the coincidence of the Pleiades and the sun rising at the same time as the spring equinox would have happened in 2278 BC.: 

   According to this, the visible setting of the Pleiades at sunrise on the same day as the autumn equinox would have occurred in 2278 BC. At this time, the equilux was, for Stellarium purposes, the 6th April, and the Pleiades rose at 4:06 am, and the sun at 4:08 am. The previous day, the 5th April had close to equal day and night, and likewise, the Pleiades and the sun rose at almost exactly the same time. Denis Pétau, if he was correct in his calculations, was therefore not referring to the heliacal rising of the Pleiades in his calculations, but to the sun and the Pleiades rising at the same time. This explains why the date he provides is different to Al Bīrūnī’s. 

  These observations made by Pétau and Al Bīrūnī, made centuries apart, suggest a shared tradition of precise astronomical knowledge. If these observations are correct, then this would show that in roughly 3000 BC, astronomy was sophisticated enough to note this coincidence, and that accurate time-keeping was taking place. This implies centuries at least of precise time-keeping and observation before this. Such precision implies not only advanced observational tools but also a cultural prioritisation of astronomy, likely tied to agricultural and religious practices. These calculations reaffirm that ancient cultures possessed a profound understanding of the cosmos, one that continues to inspire and inform our study of the past. Interestingly, the Matariki, which is the name for the Pleiades in Maori culture, are still central to marking the New Year: the heliacal rise of Matariki in June marks the start of the Maori New Year. This shows that over centuries, ongoing observation has allowed indigenous knowledge systems to be preserved, as they would have been in ancient cultures in other parts of the world. 

4. 3000 BC: A Golden Era of Astronomical Observation

   In 3000 BC astronomy was alive and well. The Pleiades were observed, and coincided at around that time with their heliacal rising in spring at the equinox or equilux. This may have started the association which lasted for many centuries between the Pleiades as bringers of spring and autumn. Bailly wrote:

   As Bailly notes, a possible reason for placing so much importance on the Pleiades may be their association with the spring equinox at some date in the past. The Pleiades are not a particularly bright constellation, and so their significance may be hard to grasp. The role of these stars in the ancient calendar may be more complicated however than simply marking the equinoxes. One of the most intriguing artefacts that highlight the sophistication of ancient astronomy is a fragment of a circular clay tablet from the Neo-Assyrian period, now held in the British Museum (catalogued as K.8538). This tablet, often referred to as a "planisphere," depicts constellations, and includes the Pleiades, and records astronomical observations. While the artefact itself dates to approximately 700 BC, research by Alan Bond and Mark Hempsell has revealed that the constellations depicted correspond to a much earlier epoch, specifically the night sky of June 29th, 3123 BC (Julian calendar). (10)

Figure 5: Fragment of a circular clay tablet with depictions of constellations (planisphere). Neo-Assyrian. https://www.britishmuseum.org/collection/object/W_K-8538

      The researchers argue that this tablet is not merely a generalised star map but a detailed record of a specific night’s sky, which includes references to a large object, interpreted as a meteor. Their analysis linked the event to a meteor impact at Köfels, a site in Austria, which would have caused significant destruction. The level of detail in the tablet allowed them to identify not just the year but the specific date of the event.

   What does this tell us? It demonstrates that by 3000 BC, people were already carefully observing, recording, and interpreting celestial events. The inclusion of constellations like the Pleiades, prominently displayed on the tablet, reinforces their importance in ancient astronomy. It also shows that these early astronomers could create star maps sophisticated enough to provide meaningful data millennia later.

   This discovery underscores a key point: in 3000 BC, the skies were being systematically monitored and documented. The Assyrian planisphere reflects a continuity of astronomical knowledge and the cultural significance placed on celestial phenomena, a knowledge base that must have required centuries of observation to develop.

   The role of the Pleiades in ancient calendars extends beyond Hesiod and the Greek world, as evidenced by the sophisticated astronomical and calendrical practices of Mesopotamia. The Babylonian MUL.APIN texts, a set of cuneiform documents dating from the seventh century BC, describe complex rules for the intercalation of months based on the Pleiades' movements. These texts are believed to have been copied from much earlier sources, potentially originating as far back as the 26th century BC.

   The MUL.APIN texts demonstrate how the visibility of the Pleiades (referred to in Sumerian as MUL.MUL, meaning "stars") was used to regulate the Babylonian calendar. Specifically, the Pleiades helped determine whether a year would have the standard twelve lunar months or require the intercalation of a thirteenth month. This leap rule system aligned the lunar calendar with the solar year over a 19-year Metonic cycle, in which seven additional lunar months were added.

   The Babylonian leap rules for the Pleiades are recorded in lines 8 to 11 of the second clay tablet of the MUL.APIN series:

1. Line 8: "When on the first Nisannu Pleiades and moon are in balance, this year is normal."

2. Line 9: "When on the third Nisannu Pleiades and moon are in balance, this year is full."

3. Line 10: "When the Pleiades rise on the first Ajaru, this year is normal."

4. Line 11: "When the Pleiades rise on the first Simanu, this year is full."

   Although some portions of these lines have been damaged, they can be reconstructed based on context and other sources. These rules illustrate how the ancient Babylonians carefully observed the Pleiades and integrated their movements into their timekeeping systems. Such precision was critical for maintaining the alignment of their calendar with agricultural and religious cycles. The importance of the Pleiades in this system also reflects their broader significance in the ancient world as markers of time and seasonal change. The importance of the Pleiades in ancient calendar systems may have gone beyond simply rising and setting at dawn and dusk in spring and autumn.

5. The Pleiades in ancient calendar around the world

All around the world, the Pleiades were associated with clendars, in particular the trcking of the cycles of the moon. In ancient Arabia, the manāzil al-qamar ("lunar mansions") were 28 stations along the moon's path through the zodiac, to track the lunar cycle. The Pleiades were called al-Ṯurayyā, and were among the most significant stars in this system, marking the third mansion. In India, the Ṛigveda (c. 1500 BC–1200 BC), one of the oldest extant texts in the world, describes the nakṣatra system, which divided the ecliptic into 27 or 28 lunar mansions, each associated with a prominent star or asterism. The Pleiades were the third nakṣatra. The ancient Chinese xiu (宿) system divided the ecliptic into 28 lunar mansions, and there the Pleiades were part of the mansion called Mao (昴), the fourth lunar lodge. Early textual evidence for this system appears in the Shujing (Book of Documents) and later in the Shiji (Records of the Grand Historian) by Sima Qian (c. 100 BCE), but its origins are much older, possibly extending to the Shang Dynasty (c. 1600–1046 BCE)s. The Maya and Aztec calendars did not explicitly employ a 28-mansion system like those of Arabia, India, or China, but they integrated the Pleiades into their larger cosmic framework. Among the Maya, the Pleiades (known as Tzab or the Rattlesnake Tail) marked key celestial events, including zenith passages and the resetting of their 260-day Tzolk'in calendar. The 52-year Calendar Round, a synthesis of the Tzolk'in and the Haab', was thought to synchronise with the Pleiades' heliacal rising, aligning with lunar and solar cycles. Together, this evidence paints a picture of a widespread sophisticated astronomical system in the ancient world. The Pleiades' role in dividing and regulating time was not a regional phenomenon but a widespread feature of the ancient world. The fact that the Pleiades held such importance for civilisations in India, Mesopotamia, Greece, and Arabia suggests that astronomical knowledge around 3000 BC was not only advanced but also widely shared.

5. The Pleiades demonstrate a shared ancient worldwide culture

The stars of the Pleiades form an asterism that is recognised across diverse cultures, and is steeped in myth and symbolism. Commonly associated with siblings, most often sisters, though sometimes brothers or children, these stars frequently number six or seven in legends, with the "missing" star often linked to shame, loss, or transformation. Johnson D has observed:

   The stars are most often interpreted as siblings, sometimes as children, sometimes girls, sometimes boys. Many cultures view the Pleiades as a group of sisters fleeing pursuers. The Greek myth tells of the Seven Sisters chased by Orion, while the Maori describe Matariki as a mother with six daughters. Aboriginal Australian narratives often depict the sisters fleeing unwanted male advances.

In many narratives, seven sisters run away from a man or group of men, represented as the what we know refer to as the constellation Orion.

 In Cherokee and Iroquois stories, the Pleiades are boys or children ascending to the sky after play.

  In The Palm and the Pleiades, Dr. Stephen Hugh-Jones collected a Barasana myth, from the Amazon, in which the mother of the sky, Romi Kumu, is described as a gourd, but the gourd is special. By nightfall she has grown old, and her youth and beauty are restored each morning. The gourd gets the credit for this. The Pleiades are equated with this gourd and its fecundity.

The number varies from six to seven. In the Greek myths, several of Olympian gods were engaged with the seven heavenly sisters. Merope, the youngest of the seven Pleiades, married Sisyphus and, becoming mortal, faded away: this is how the myth explains why in the Pleiades star cluster only six of the stars shine brightly and the seventh, Merope, shines dully. The Nez Perce, in North America, recount a grieving sister veiling herself, explaining why only six stars are visible. In both these accounts, from different continents, the seventh star is associated with grief or shame to explain its disappearance from what was once a group of seven. It has been theorised that the Pleiades' myths of "seven sisters, but only six visible" may stem from prehistoric observations when Pleione, a dimmer star in the cluster, was more distinctly visible, possibly as far back as 100,000 BC.

   Another common theme throughout the world is the association of the Pleiades with agriculture. In Sub-Saharan Africa, they are "the planting stars," marking the rainy season and time to sow crops. Similarly, the Andean Quechua associate the Pleiades with abundance, calling them "Qullqa" (storehouse), while Bantu languages use terms meaning "cultivation." In Ukrainian folklore, the Pleiades name Stozhary (Стожари) can be etymologically traced to stozharnya (стожарня) meaning a 'granary', 'storehouse for hay and crops', or can also be reduced to the root sto-zhar (сто-жар), meaning 'hundredfold glowing' or "a hundred embers".

The Pleiades appear not only in myths but also in ancient art and artefacts, offering a glimpse into humanity's deep connection with the stars. In France, the "Salle des Taureaux" of the Lascaux caves (circa 15,300 BC), a cluster of dots above an aurochs’ back is thought to represent the Pleiades above Taurus, suggesting a very old awareness of the constellation Taurus, as a bull-like creature, similar to today, and of the asterism within it, or perhaps next to it, of the Pleiades playing an important role. The Nebra Sky Disk, a Bronze Age artefact from Germany, is much closer to our time in age, dating from circa 1600 BC. It depicts the Pleiades as a cluster of dots, confirming their importance in prehistoric European sky lore.

Conclusion

   In light of the sophistication of astronomy in about 3000 BC, and probably much before that, can we consider the ancient monuments of the Neolithic and Bronze Age as testaments to the intellectual and cultural advancements of people well versed in astronomy? The historical texts and archaeological evidence discussed here suggest that the builders of megalithic structures were not primitive or simplistic in their understanding of the world. Rather, they were attuned to the rhythms of the sky, using the movements of the stars and planets as markers of time, seasons, and and sophisticated systems to base their calendars on.

  The observations made by Al Bīrūnī and Denis Pétau in the 11th and 17th centuries show that it was known at those times that astronomy was sophisticated in 3000 BC. What happened since then, to make people believe that the people of the third millenium BC, including the builders of Stonehenge and Avebury, were howling barbarians, to re-use Atkinson’s phrase? There may have been a shift in attitude towards the understanding of the distant past since the 17th century, in which it has become acceptable to look down on pre-historical people. It continues to be controversial to claim that people in 3000 BC were intelligent and sophisticated, but the evidence suggests that this is unnecessary. The monuments they left behind, aligned with the stars, may not have been just markers of time, but symbols of a deeper relationship between humankind and the heavens, a relationship that, in many ways, still resonates with us today. Amazingly, many ancient observations and practices related to the Pleiades live on in the cultures of indigenous people of the Americas, Australia, New Zealand, as well as in India and other parts of the world.

   Why should one particular section of the sky, one cluster of stars, be so significant? All the stars move around the sky in the same way over the course of a year, changing their respective positions only over long periods of time. Any star could have been chosen to mark a point in the zodiac. As Bailly remarked: 

Astronomically and culturally, the Pleiades must have played an important role for a long time, and this applies to every part of the world where myths, calendars or astronomical observations from the past have survived. Some cultures also describe the Pleiades as their place of origin. For example, also in North America, the Ojibwe believe the Pleaides are a gateway between the earth and the "star world", through which the star people come to speak to seers during ceremonies. Wilfred Buck, a Cree science specialist from Opaskwayak Cree Nation in Canada, has described the Pleiades in this intriguing way: 

Whatever the significance of the Pleiades may have been, over the centuries, it is clear that looking at a few ways in which they have been used in calendars, depicted in myth and art, and shown in star maps, that astronomy was in good shape in 3000 BC, and not only that, it may have played an important part of people's lives.

Notes

1. Burl, Aubrey, 1979, Prehistoric Avebury, New Haven : Yale University Press https://archive.org/details/prehistoricavebu00burl/page/n5/mode/2up

2.  Ibid.

3.  Richard Atkinson, 1979, Stonehenge: A New Explanation of Its Origins and Meanings, Penguin Books

4.  Pseudo-Hyginus, Astronomica 2. 21, quoted in https://www.theoi.com/Nymphe/NymphaiPleiades.html

5. Hesiod, The Homeric Hymns, translated Hugh G. Evelyn-White 1914, https://www.gutenberg.org/files/348/348-h/348-h.htm#chap01

6. The transit of the sun is 12 hours per day at the equilux. In 700 BC, the date for this according to our calendar, and on Stellarium, is 24 March. 

7. Richard Hinckley Allen, 1963, Star Names — Their Lore and Meaning, Dover Publications; Revised edition, https://penelope.uchicago.edu/thayer/e/gazetteer/topics/astronomy/_texts/secondary/allsta/home.html

8. Jean-Sylvain Bailly, 1775, Histoire de l’Astronomie Ancienne, Paris Frères Debure, p 477

9.  Ibid. p 479

10. Cuneiform clay tablet translated for the first time, Press release issued: 31 March 2008, https://www.bristol.ac.uk/news/2008/212017945233.html

11. Bailly p 477-478

12. From “'We come from the stars': How Indigenous peoples are taking back astronomy”, 2019, article by Nicole Mortillaro, CBC News, https://www.cbc.ca/news/science/indigenous-astronomy-1.5077070

13. Johnson D. , 2011, Interpretations of the Pleiades in Australian Aboriginal astronomies. Proceedings of the International Astronomical Union. 2011;7(S278):291-297.